Intravascular disruption system with improved durability, efficiency, and variability of pressure output

Abstract

Various embodiments of systems, methods and devices are provided for destroying calcified lesions within anatomical conduits, with an exemplary system generating an electrical arc between two spaced apart electrodes positioned within a fluid-filled balloon.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Provisional Application No. 63 / 477,007, filed December 23, 2022, entitled "INTRAVASCULAR LITHOPLASTY AND / OR ANGIOPLASTY BALLOON SYSTEM WITH IMPROVED BALLOON MOUNT AND ELECTRODES."

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT none

[0003] The present invention relates to systems, devices, and methods for destroying calcified lesions within anatomical conduits. In one embodiment, an electrical arc is generated between two spaced electrodes disposed within a fluid-filled member to create a pressure wave. In another embodiment, the fluid-filled member can be expanded and contracted to open occluded blood vessels, including, but not limited to, calcified occlusions. [Background technology]

[0004] Various techniques and devices have been developed for use in the removal or repair of tissue within arteries and similar body passageways, including the removal and / or disruption of calcified lesions formed within the passageways and / or within the walls that define the passageways. A common purpose of such techniques and devices is to remove atherosclerotic plaque within a patient's arteries. Atherosclerosis is characterized by the buildup of fatty deposits (atheromas) in the intimal layer (i.e., beneath the endothelium) of a patient's blood vessels. Over time, these deposits often begin as relatively soft, cholesterol-rich atheromatous material, which harden into calcified atherosclerotic plaques, often within the vessel walls. Such atheromas restrict blood flow and make the vessel less pliable than normal, and are therefore often referred to as stenotic lesions or stenoses, with the obstructing material being referred to as stenotic material. If left untreated, such stenosis can lead to angina, hypertension, myocardial infarction, stroke, and the like.

[0005] Angioplasty, or balloon angioplasty, is an intravascular procedure that widens and treats narrowed or blocked arteries or veins, typically to treat atherosclerosis. Typically, a folded balloon is passed through a pre-placed catheter and over a guidewire into the narrowed occlusion, then inflated to a fixed pressure. The balloon forces the occlusion open until the occlusion within the vessel and surrounding muscle wall yields to the radial force exerted by the expanding balloon, widening the vessel to an inner diameter similar to that of the native vessel in the occluded area and thereby improving blood flow. Known intravascular lithotripsy (IVL) devices generally include a voltage pulse generator mounted on a catheter and in operative communication with one or more pairs of electrodes within the inflatable balloon.

[0006] Intravascular lithotripsy systems, devices, and methods have been described by the applicant, see PCT Application No. PCT 2022 / 074607, filed August 5, 2022, entitled "INTRAVASCULAR LITHOTRIPSY BALLOON SYSTEMS, DEVICES AND METHODS," the entire contents of which are incorporated herein by reference.

[0007] As shown in FIG. 1 , a schematic layout of several portions of an exemplary IVL system 12 is provided. The exemplary IVL system 12 comprises a catheter assembly 114 including an elongate body embodied as a catheter having a guidewire 15, and a fluid-filled member 16 configured to contain an electrically conductive fluid therein, exemplified by an inflatable balloon disposed near one end of the body and configured to receive inflation fluid to facilitate IVL treatment. Disposed within the exemplary balloon 16 are a set of dischargeable, spaced-apart electrodes 18, at least some of which are spaced apart by gaps 17 to generate a spark or electric arc between the spaced-apart electrodes 18.

[0008] Embodiments of the IVL system described herein may be used in conjunction with electrodes contained within a fluid-filled member 16 configured to contain a fluid, e.g., a conductive fluid, therein. An embodiment of the fluid-filled member 16 may include an inflatable balloon, as shown in FIG. 1, which may be flexible or non-compliant and serves to contain the fluid such that the spaced apart electrodes 18 are immersed in the contained fluid. Additionally, the fluid-filled member 16 may be comprised at least in part of a rigid and / or non-compliant fillable member. In other embodiments, the fluid-filled member 16 may contain a fluid therein, with the spaced apart electrodes 18 positioned or immersed in the contained fluid.

[0009] Alternatively, embodiments of the IVL system control of the present disclosure may be used in conjunction with electrodes that are not located within or surrounded by a fluid-filled or fillable member 16. In these embodiments, the IVL system may include spaced apart electrodes 18 that may be continuously or periodically exposed to saline or other fluid, and during this exposure, the IVL system may generate an electric arc between the spaced apart electrodes 18.

[0010] The spaced apart electrodes 18 are disposed in communication with an electrical pulse-generating system 20 (as suggested by the dashed conductors) to receive high-voltage electrical energy for spark generation and to produce pressure waves for IVL treatment. In this exemplary embodiment, one electrode may be grounded and the other may be supplied with high voltage from the electrical pulse-generating system 20, although in some embodiments, any voltage difference may be applied. The electrical pulse-generating system 20 includes an IVL control system 22 comprising a processor 24 configured to execute instructions stored in a memory 26 and communicate signals via a circuit 28 for IVL operation under the direction of the processor. The processor 24, memory 26, and circuit 28 are disposed in communication with each other (as suggested by the dashed lines) to facilitate the disclosed operations.

[0011] Proper control of such high-energy systems may also be required to achieve sufficient energy at the discharge site. Given the high-energy environment and the microscale duration of the electron discharge, desirable energy control within such IVL devices and systems can be challenging. Furthermore, adaptive control methodologies may benefit the effectiveness of IVL. Adjustable energy delivery can increase efficient power application, potentially reducing risk to the patient. For example, starting from a predetermined starting voltage threshold, an attempt may be made to define a predetermined upper voltage threshold to form an acceptable voltage window. The acceptable voltage window may be coupled to a generated series of voltage pulses whose magnitudes are confirmed to be within the acceptable voltage window. For example, if the magnitude of the generated series of voltage pulses falls below the predetermined upper voltage threshold, the target voltage may be increased by a predetermined amount, and another series of generated voltage pulses is performed. Embodiments of IVL systems, devices, and methods within the present disclosure include operations for adjusting the total electrical energy delivered to the electrode set for a given pulse. The applicant has described such control systems for intravascular disruption systems, devices, and methods. See PCT Application No. PCT 2023 / 79209, filed November 9, 2023, entitled "CONTROL OF IVL SYSTEMS, DEVICES AND METHODS THEREOF," the entire contents of which are incorporated herein by reference.

[0012] A portion of an exemplary known competitive IVL device is shown in cross section in FIG. 2, particularly as viewed in cross section along a line cut through the IVL balloon surrounding the catheter body.

[0013] Thus, the inflation port of the prior art is in fluid communication with the filling lumen / passageway. The filling lumen / passageway of the competitive IVL device of FIG. 2 is formed between the inner surface of the catheter body and the outer surface of the sleeve surrounding the wire conductors (which terminate in electrodes located along the catheter and within the balloon). Therefore, the wire conductors of this known device are not exposed to the fluid within the filling lumen / passageway. The electrodes located within the balloon and electrically connected to the wire conductors are not covered by the surrounding sleeve and are therefore not exposed to the fluid within the balloon. Additionally, this known competitive device includes an angioplasty balloon bonded to the outer surface of the catheter body at both the proximal and distal ends of the balloon, and the filling lumen / passageway to the interior of the balloon is formed within the catheter body and defined by the space between the sleeve and the inner surface of the catheter body. Therefore, this known competitive IVL balloon is bonded to a single structure, i.e., the outer surface of the catheter body, at its proximal and distal ends.

[0014] Additionally, the known competitive IVL device of Figure 2 includes a catheter body and a guidewire member (defining a guidewire lumen), both of which extend through the balloon. Both of these structures continue distally beyond the distal end of the balloon to the distal tip. As a result, the distal tip of this known competitive device has stiffness and deformability that can be improved to improve the device's ability to translate through tortuous vasculature and reduce the likelihood of damaging the vasculature during translation.

[0015] Additionally, the sleeve shown in FIG. 2 adds layers of material that increase the thickness and complexity of the crossing profile and occupy a portion of the area of ​​the filling lumen / passageway, thereby reducing the available volume of the filling lumen / passageway during inflation and / or deflation cycles.

[0016] FIG. 3 graphically illustrates the drop in impedance of a leading flash of current across a spark gap defined between two spaced-apart electrodes in an IVL system such as that shown in FIG. 1 as the leading flash of current develops into an electric arc between the spaced-apart electrodes after a voltage is applied to one of the two spaced-apart electrodes. This then results in a sharp peak in power loss in the electric arc, while both the voltage and current between the electrodes are relatively high. The current peaks and the voltage drops, both occurring very quickly, signifying the existence or occurrence of an electric arc between the spaced-apart electrodes. The peak in power loss in the electric arc represents a relatively short time interval during which all of the meaningful work of heating the growing leading flash into an arc is done. The schematic diagram of FIG. 3 is illustrative of one embodiment of an IVL procedure that generates pressure waves.

[0017] It would be advantageous to provide an IVL system and / or device that reduces the risk of trauma during translation of the angioplasty balloon to the anatomical location of interest and reduces the structural complexity of the fracturing system.

[0018] Additionally, it would be advantageous to provide an IVL system and / or device with a reduced crossing profile, a more flexible tip, and a kink-resistant shaft.

[0019] Known IVL devices also include a spark gap between the electrode pair, which facilitates a spark or arc of current from the first electrode in the electrode pair across the spark gap to the second electrode when a sufficiently high voltage is applied to the first electrode. This process results in material loss or erosion from each electrode in the electrode pair. Known spark gaps are typically arranged axially, i.e., in an axial spark gap configuration, the end faces of the wire conductors are spaced apart and positioned opposite each other. In this case, the electric arc engages the end face or distal surface of at least one electrode in the electrode pair. Continuous arcing across the spark gap during an IVL procedure using these known devices results in material erosion from each electrode involved in the electric arc. Each of these arcs slightly enlarges and / or shorts the spark gap, resulting in a substantial increase in the size of the spark gap over the entire procedure, which can lead to unpredictability in the generation of the electric arc. Alternatively, the first and second electrodes may be concentrically arranged, with the spark gap defined radially, where the first and second electrodes are not arranged along a common radial or circumferential plane. As demonstrated herein, this arrangement produces a relatively highly variable pressure output. Additionally, known IVL devices generate a resulting pressure output, or "shock waves" or "pressure waves," that decreases in magnitude over a series of electrical arcs as the IVL procedure is performed. Furthermore, the highly variable pressure output generated by known IVL devices can lead to unpredictable or undesirable results, and the variability in pressure output can stress the balloon material, contributing to balloon instability over time. Furthermore, known IVL coronary devices are configured to generate a maximum total number of 120 pulses per catheter at a frequency of 1 Hz. Known IVL peripheral devices are configured to generate a maximum total number of 300 pulses per catheter at 1 Hz.

[0020] It would be advantageous to provide an IVL device or system designed to maintain a desired spark gap distance between spaced electrodes throughout the entire IVL procedure and generate a tightly controlled output pressure with a much narrower data spread from high to low data points and a lower standard deviation compared to known IVL devices.

[0021] It would also be desirable to provide an IVL device or system that is more durable and efficient than known devices through structural and operational improvements that result in an IVL device or system that can deliver up to 300 or more voltage pulses per catheter in some embodiments, and up to 500 voltage pulses per catheter in other embodiments, at a frequency of 1-5 Hz, with 2 Hz being a preferred frequency.

[0022] It would be advantageous to provide an IVL device or system having a catheter with key features that allow for improved pushability and kink resistance, particularly in the area of ​​the balloon, as well as a reduced crossing profile in at least that area.

[0023] Various embodiments of the present invention specifically address the above-mentioned advantages.

[0024] The following drawings are illustrative illustrations of certain embodiments and are not intended to limit the disclosure in any way. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a schematic diagram of an exemplary IVL device. [Figure 2] 1 is a cutaway view of a known IVL device. [Figure 3] FIG. 2 is a diagram of typical timing of applied voltage and current during application of a voltage between spaced apart electrodes and creation of an electric arc. [Figure 4] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 5] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 6] FIG. 10 is a side cutaway view of a distal portion of an exemplary embodiment of the present disclosure. [Figure 7A] FIG. 1 is a side cutaway view of an exemplary embodiment of the present disclosure. [Figure 7B] FIG. 1 is a side cutaway view of an exemplary embodiment of the present disclosure. [Figure 8] FIG. 10 is a side cutaway view of a portion of a distal region of an exemplary embodiment of the present disclosure. [Figure 9] FIG. 1 is a partial cutaway view of a portion of an exemplary embodiment of the present disclosure. [Figure 10] FIG. 7 is a side cutaway view of a portion of FIG. 6. [Figure 11] FIG. 11 is a side cutaway view of the embodiment of FIG. [Figure 12A] FIG. 1 is a diagram of one embodiment of a portion of a system of the present disclosure. [Figure 12B] FIG. 1 is a diagram of one embodiment of a portion of a system of the present disclosure. [Figure 12C] FIG. 1 is a diagram of one embodiment of a portion of a system of the present disclosure. [Figure 12D] FIG. 1 is a diagram of one embodiment of a portion of a system of the present disclosure. [Figure 13A] FIG. 1 is a diagram of one embodiment of a portion of a system of the present disclosure. [Figure 13B] FIG. 1 is a diagram of one embodiment of a portion of a system of the present disclosure. [Figure 14A] FIG. 1 is a side cutaway view of one embodiment of the present disclosure. [Figure 14B] FIG. 14B shows a portion of the device shown in FIG. 14A. [Figure 15A] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 15B] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 15C] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 15D] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 15E] FIG. 1 is a cross-sectional view of an embodiment of the present disclosure. [Figure 16A] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 16B]FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 16C] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 16D] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 17A] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 17B] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 17C] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 17D] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 18A] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 18B] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 19A] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 19B] FIG. 1 is a diagram of an embodiment of the present disclosure. [Figure 20] FIG. 1 is a side view of an embodiment of the present disclosure. [Figure 21] FIG. 1 is a schematic diagram of an embodiment of the present disclosure. [Figure 22] FIG. 1 illustrates a top cutaway view of one embodiment of the present disclosure. [Figure 23] FIG. 1 is a block diagram of one embodiment of the present disclosure. [Figure 24] FIG. 1 is a pressure plot comparing a test IVL device with a known IVL device. [Figure 25] FIG. 10 is a force tracking plot comparing the tracking forces through a tracking device of a test IVL catheter and a known IVL catheter. DETAILED DESCRIPTION OF THE INVENTION

[0026] FIG. 4 illustrates one embodiment of an IVL system 100 of the present disclosure. A voltage pulse generator 110 is provided and is in operative connection and communication with a controller 112 configured to provide programmed operating instructions to the voltage pulse generator 110 and a fluid reservoir / fluid pump device 114. The controller 112 and voltage pulse generator 110 are in operative electrical communication with wire conductors and electrode pairs, as described above, with the wire conductors disposed along the length of the catheter and the electrode pair disposed within an inflatable balloon disposed at or near the distal end of the catheter structure. The catheter and balloon structure are represented diagrammatically by element number 116. A hub 118 enables operative connection and communication between the controller 112, the fluid reservoir / pump 114, and the voltage pulse generator 110. Additionally, a connector 120 is in operative connection and communication with the controller 112 and provides operative electrical connection and communication with the wire conductors and electrode pairs. The controller 112 may include a processor for executing programmed instructions, for example, initiating voltage pulses at a predetermined magnitude and frequency and in a predetermined pattern of pulses and magnitudes. The processor may be in operative communication with a memory and a display. In some embodiments, the hub 118 may enable over-the-wire guidewire access through a lumen defined within the catheter. In preferred embodiments, rapid exchange (RX) access is provided. Some embodiments of the controller 112 may include an EPROM with programmed instructions, for example, but not limited to, initiating voltage pulses at a predetermined magnitude and frequency and in a predetermined pattern of pulses and magnitudes.

[0027] 22 and 23, some embodiments may include a handle that may include an EPROM with programmed instructions for, for example, but not limited to, initiating voltage pulses at a predetermined pattern of pulses and magnitudes at a predetermined magnitude and frequency. The EPROM may be in operative communication with and connected to a processor that executes the programmed instructions, a memory in operative communication with the processor and, in some embodiments, the EPROM, and a console that includes a display. In some embodiments, the hub 118 may enable over-the-wire guidewire access through a lumen defined within the catheter.

[0028] 5 shows an exploded side view of an IVL system 100 including a handle having a connector 120 configured to connect to the voltage pulse generator 110 of FIG. 4 and a console as described above. A removable mandrel M is shown inserted through a guidewire lumen defined along a portion of the catheter shaft, extending proximally through the flexible distal tip and through the defined guidewire lumen of the catheter.

[0029] An embodiment of the distal portion of the catheter and balloon element 116 of the exemplary IVL system 100 of FIGS. 4 and 5 is shown in FIGS. 6-11.

[0030] As best seen in FIG. 7A, an inflatable balloon 200 is provided, comprising a cylindrical proximal section 202, a cylindrical distal section 206, and an inflatable portion 210, the inflatable portion 210 comprising an unjoined section 203 of the cylindrical distal section 206, a tapered proximal section 212, a tapered distal section 214, and a substantially cylindrical section 216 disposed between the tapered proximal section 212 and the tapered distal section 214.

[0031] The proximal portion 207 of the cylindrical distal section 206 of the balloon 200 surrounds and is joined or sealed in watertight engagement against the outer surface of the elongate member 220, as best shown in Figure 6. The distal region of the cylindrical distal section 206 extends beyond the distal end of the elongate member 220 and is, for example, extruded, to form an atraumatic soft tip 218.

[0032] The proximal portion 204 of the balloon's cylindrical proximal section 202 surrounds the non-tapered outer surface 234 (see FIG. 8 ) of the tapered outer member 230, is sealed or bonded in watertight engagement with the outer surface 234, is not sealed or bonded to any portion of the elongate member 220 received therein, and extends distally from the distal end of the tapered outer member 230. The distal length, comprising the unbonded section 203 of the cylindrical proximal section 202 of the balloon 200, surrounds the distal tapered section 232 of the tapered outer member 230 but is not sealed or bonded to any portion of the tapered outer member 230. As a result, the inflatable section of the balloon 200 includes the unbonded section 203 of the cylindrical proximal section 202, the proximal tapered section 212, the distal tapered section 214, and a substantially cylindrical section 216 disposed between the proximal tapered section 212 and the distal tapered section 214.

[0033] Tapered outer member 230 has an outer diameter that is larger than the outer diameter of elongate member 220 and is configured to receive elongate member 220 .

[0034] Additionally, a length of fluid transfer pipe P is defined along the length of the device between the concentric arrangement of the outer surface of the elongate member 220 and the inner surface of the tapered outer member 230. The remainder of the fluid transfer pipe P is defined proximally along the catheter shaft. The fluid transfer pipe P is provided with a dedicated path for fluid communication between the fluid reservoir / pump 114 and the inflatable section 210 of the balloon 200. The fluid transfer pipe P terminates distally against the distal end of the tapered outer member 230, and defines an opening O at the distal end for fluid flow into and out of the balloon 200.

[0035] It is important to note that the distal end of the tapered outer member 230, and therefore the opening O for fluid flow, extends distally beyond the distal end of the balloon's proximal cylindrical section 202. As a result, the balloon's proximal cylindrical section 202 surrounds at least a portion of the proximal non-tapered or cylindrical section 234 of the tapered outer member 230 and is sealed or joined to the outer surface of the non-tapered or cylindrical (proximal) section 234 in a watertight seal. However, the distal end region of the tapered outer member 230 is not surrounded by the balloon's proximal cylindrical section 202. Instead, the distal end region of the tapered outer member 230 and its opening O extend into the proximal tapered section 212 of the balloon 200.

[0036] As a result of the watertight sealing mechanism described above and the location of the opening O for fluid flow into and out of the inflatable portion 210 of the balloon 200, the proximal cylindrical section 202 of the balloon 200 does not participate in the movement of fluid into or out of the inflatable portion 210 of the balloon 200. Likewise, the inflatable portion 210 of the balloon 200 does not participate in the inflation / deflation or degassing of fluid, nor in the movement of fluid into or out of the inflatable portion 210 of the balloon 200. The inflatable portion 210 simply receives incoming fluid from the opening O at the distal end of the tapered outer member 230 and delivers outgoing fluid to the opening O.

[0037] FIG. 8 shows the distal portion of the tapered outer member 230, which includes a tapered section 232 with a taper angle α. The tapered section 232 in this embodiment constitutes the non-bonded section 203 of the balloon 200; the proximal cylindrical section 203 of the balloon 200 (see FIG. 7A ) surrounds a portion of the tapered section 232 but is not glued, bonded, or sealed to the outer surface of the tapered section 232. Proximal to the tapered section 232, the tapered outer member 230 includes a cylindrical section 234 of substantially constant diameter, shown as the bonded section, which provides an outer surface that the proximal portion 204 of the proximal cylindrical section 202 of the balloon 200 surrounds and seals or bonds in watertight engagement. The side of the fluid transfer pipe P, as described above, has a resulting inner diameter, shown in dashed lines, and the pipe P terminates in an opening O at the distal end of the tapered outer member 230. As shown by the inner set of dashed lines, the inner diameter tapers distally within tapered section 232. In other embodiments, pipe P may be of substantially constant diameter throughout both cylindrical section 234 and tapered section 232, and the wall thickness of the pipe may decrease or thin as it moves distally in tapered section 232 while maintaining a constant inner diameter throughout cylindrical section 234 and tapered section 232. In other embodiments, as in FIG. 8 , the outer profile of pipe P may taper downwardly at a taper angle α in tapered section 232. In some embodiments, the inner diameter of pipe P may be of constant diameter.

[0038] As shown in FIGS. 7A and 7B, and with continued reference to FIGS. 6, 8, 10, and 11, the cylindrical proximal section 202 of the balloon 200 has a length L1 and an outer diameter OD1. The length L1 of the cylindrical proximal section 202 surrounds the tapered outer member 230, but only a proximal portion 204 of the cylindrical proximal section 202 is bonded or sealed in a watertight configuration against the outer surface of the elongate member. The proximal portion 204, also referred to as the proximal watertight seal or bonded portion 204, has a length L2 that is less than L1. Finally, the cylindrical proximal section 202 further comprises an unbonded section 203 at its distal end, having a length L3 that surrounds the tapered outer member 230 but is not bonded or sealed to the elongate member, where L3 is less than L2 and L1, and L2 + L3 is equal to L1.

[0039] Balloon 200 further comprises a cylindrical distal section 206 having a total length of L4, including distal tip 218. Without distal tip 218, a proximal portion 207 of cylindrical distal section 206, which surrounds and is sealed or joined in watertight engagement against the outer surface of elongate member 220, has a length of L5, which is less than L4. Thus, distal tip 218 extends a distance distally beyond the distal end of elongate member 220 to provide an atraumatic tip to facilitate translation through the vascular system.

[0040] As explained above, the inflatable portion 210 of the balloon 200 comprises an unbonded section (length L3) 203, a tapered proximal section 212, and a tapered distal section 214, with a substantially cylindrical section 216 disposed therebetween. The length of the inflatable section is therefore L6, which includes the proximal cylindrical unbonded section 203 of length L3, the proximal tapered section 212 of length L7, the distal tapered section 214 of length L8, and the substantially cylindrical section 216 of length L9, for a total inflatable section length of L6.

[0041] The tapered outer member 230 may taper down to a smallest outer diameter OD2 at its distal end that is smaller than outer diameter OD1, which is essentially the outer diameter of the proximal cylindrical section 202 and the outer diameter of the non-tapered portion 234 of the tapered outer member 230. In this embodiment, the inner diameter of the balloon's cylindrical proximal section 202 may be substantially equal to the outer diameter of the tapered outer member at OD1, which is the non-tapered portion 234 of the tapered outer member to which the proximal cylindrical section is watertightly joined or sealed. Similarly, the inner diameter of the proximal portion 207 of the balloon's cylindrical distal section 206, which is watertightly joined or sealed to the elongate member 220, may be substantially equal to the outer diameter of the elongate member 220 at OD3.

[0042] As can be seen in Figures 6 and 7A, the outer diameter of the outer member, i.e., OD1, to which the cylindrical proximal section of the balloon is sealed or joined, may be larger than the outer diameter of the elongate member, which has an outer diameter OD3.

[0043] As noted, elongate member 220 is received within tapered outer member 230. As a result, balloon 200 is sealed against two separate structures: proximally, balloon 200 is sealed against non-tapered outer surface 234 of outer member 230, while distally, balloon 200 is sealed against the outer surface of elongate member 220.

[0044] The distal tip 218 of the balloon is preferably flexible and includes a conduit defined therethrough that aligns with the conduit defined through the elongate member, among other things, to allow guidewire access.

[0045] In some embodiments, the larger proximal outer diameter OD1 compared to the smaller distal outer diameter OD3 may create a taper angle μ of the tapered proximal section of the balloon that is different from, e.g., smaller than, the taper angle β of the tapered distal section of the balloon. These taper angles are measured relative to the dashed lines in FIG. 7A, which are collinear with the non-tapered outer surface of the outer member (taper angle μ) and the outer surface of the elongate member (taper angle β). In some embodiments, the length L7 of the tapered proximal section may be less than the length L8 of the tapered distal section.

[0046] Because of these exemplary relative dimensions, as shown in both FIGS. 7A and 7B , embodiments of the balloon 200 within the inflatable section 210 may be longitudinally asymmetric. Specifically, the inflatable section 210 may be longitudinally asymmetric with a smaller taper angle μ in the proximal tapered section 212 than the taper angle β in the distal tapered section 214 of the balloon 200, which may help facilitate access to narrow lesions. In other embodiments, the taper angles μ and β may be substantially the same. Additionally, embodiments of the distal cylindrical section 206 of the balloon 200 include an outer diameter at OD3 that is smaller than the outer diameter of the proximal cylindrical section 202, which may also facilitate access to narrow lesions. Stated another way, the crossing profile of the device distal to the substantially cylindrical section 216 of the balloon 200 is smaller than the crossing profile of the device proximal to the substantially cylindrical section 216 of the balloon 200.

[0047] 7B and 14B, the elongate member 220 to which the balloon 200 is distally sealed comprises a polyimide core lined on the inner surface with polytetrafluoroethylene, commonly known as PTFE. The outer surface of the polyimide core is lined with 72D Pebax®. The electrode support members ES (proximal), ES' (distal) may be stainless steel and coated with an insulating material such as a polymer or a blend of polymers or other materials, including but not limited to adhesive, polyimide, or other high-temperature resistant, flowable, non-conductive materials.

[0048] Exemplary dimensions of the region of balloon 200 may include the length of extension of the distal end of outer member 230 a distance into inflatable section 210. An exemplary distance the distal end of the outer member extends into the inflatable section is 0.794 mm, although other extension distances are within the scope of the present disclosure.

[0049] The balloon may be made of nylon or a similar material, hi some embodiments, the balloon material is uncoated, which may allow for more efficient transmission of energy from the pressure wave therethrough.

[0050] Additionally, the presence of the tapered outer member 230, which adds stiffness to the device, the unbonded section 203 of the balloon 200, and the tapered section 232 of the tapered outer member 230, which allows for a small crossing profile in the rolled balloon configuration, all function to provide additional pushability and strength in the region of the outer member, and further act to prevent kinking of the rolled balloon device during advancement through the patient's vascular system, both of which are highly advantageous.

[0051] 6 and 9-11, proximal and distal marker bands BP and BD may be provided within the inflatable portion 210 of the balloon and may be positioned around the elongate member 220 at or near the transitions from the proximal and distal tapered sections 212, 214, respectively, to the substantially cylindrical section 216. Additionally, a first proximal electrode support member ES is located along the elongate member 220 within the inflatable portion 210 at a location that may be closer to the proximal side of the balloon 200. In some embodiments, a single electrode support member ES may be provided, as will be further described below.

[0052] A second (distal) electrode support member ES' may be located along elongate member 220 within inflatable portion 210, distally spaced from the first (proximal) electrode support member ES, closer to the distal side of balloon 200. The two electrode support members ES and ES' are operatively and electrically connected by wire conductors W, which are in operative electrical communication with voltage pulse generator 10, as further described below.

[0053] FIG. 9 shows a portion of elongate member 220 and outer member 230 with balloon 200 removed. Here, first and second electrode support members ES, ES′ are shown in more detail with their wire conductors W connected in a series connection. Each electrode support member ES, ES′ comprises a body B of conductive material coated with insulating material I and includes at least one, and preferably two, cutouts, as described further below. A tab or arcuate region is defined on one of the two longitudinal sides of each cutout, and the wire conductors have an insulating coating except for the distal-most ends of the wire conductors, which lack insulation. As described further below, a spark gap is formed between the exposed wire of the wire conductor and the tab or arcuate region of the cutout in electrode support member ES, ES′.

[0054] Each electrode support member may include two rotationally spaced cutouts having spark gaps, and the cutouts may be rotationally spaced 180 degrees from each other or may be rotationally spaced from each other by different rotational intervals. As shown in FIG. 9 , the spark gaps formed by electrode support member ES and the spark gaps formed by electrode support member ES′ may also be rotationally spaced from each other. For example, if the spark gaps of electrode support members ES and ES′ are spaced 180 degrees from each other around the respective electrode support members ES, ES, the two electrode support members ES and ES′ may be rotated radially to ensure that all spark gaps are rotationally spaced from each other to provide circumferential coverage. In some embodiments, two or more cutouts and their respective spark gaps may be longitudinally aligned. As best shown in FIGS. 6 and 9 , electrode support members ES and ES′ may be rotated relative to each other such that their respective cutouts and spark gaps are also rotationally spaced from each other around the elongate member 220. A preferred rotational spacing may include a 90 degree rotational spacing between spark gaps along elongate member 220, although other rotational spacings are within the scope of the present invention.

[0055] 10 and 11 show cutaway views of the balloon 200 and proximal side of the catheter structure, showing the first (proximal) electrode support member ES along with the associated wire conductors W. Additionally, wire conductors returning to the positive and negative terminals of the voltage pulse generator occupy the fluid transfer pipes.

[0056] 10 also shows a proximal-most first electrode support member ES, which includes a body B of conductive material defining a cutout C1A having two opposing longitudinal sides L1, L2 and opposing proximal and distal ends PE, DE. A tab or arcuate region 250 is formed or defined along one of the longitudinal sides L1. The surface of the electrode support ES is coated with an insulating material I, except for the tab or arcuate region 250 of exposed conductive material.

[0057] As shown, wire conductor 300 includes insulation having an exposed distal wire end region 302 extending proximally from the distal end. The proximal end region of exposed wire region 302 is shown positioned within a cutout adjacent to and laterally or radially spaced from tab or arcuate region 250A. This configuration results in a spaced-apart electrode pair defining a spark gap between a lateral surface, preferably not a distal end surface, of exposed wire region 302 (which constitutes the first electrode of the illustrated spaced-apart electrode pair) and tab or arcuate region 250 (which constitutes the second electrode of the spaced-apart electrode pair). In some embodiments, a face of the distal end surface of wire conductor 300 may serve as an electrode in the above configuration.

[0058] A preferred embodiment involves an exposed lateral surface of the wire conductor located at the distal region of the wire conductor serving as one electrode of a spaced-apart electrode pair. The illustrated embodiment of FIG. 10 includes the lateral surface of the exposed wire region 302 of the wire conductor as the first electrode, meaning that current flows first to this electrode and then across the spark gap to the second electrode of the spaced-apart electrode pair. As will be explained later, this current flow may be reversed in certain spaced-apart electrode embodiments, in which case the metal region (in FIG. 10 , the embodiment is tab or arcuate region 250A) constitutes the first electrode of the spaced-apart electrode pair. In that embodiment, the lateral surface of the wire conductor constitutes the second electrode of the spaced-apart electrode pair, and current flows to the first exemplary tab or arcuate region 250A and then across the spark gap to the second electrode consisting of the lateral surface of the exposed wire region 302.

[0059] Preferred embodiments include having the surface area of ​​the first electrode and the surface area of ​​the second electrode of the spaced-apart electrode pair be substantially equal. In other embodiments, the surface area of ​​the second electrode of the spaced-apart electrode pair may be greater than the surface area of ​​the first electrode. Alternatively, the surface area of ​​the first electrode of the spaced-apart electrode pair may be greater than the surface area of ​​the second electrode.

[0060] As will be further explained, a preferred location for exposed wire region 302 is to place its distal end approximately one-half the distance between the proximal end of tab or arcuate region 250A and proximal end PE of cutout C1A. This location is shown by axis A in FIGS. 10, 17A-C, 18, and 19. In this configuration, the portion of the wire conductor directly overlying tab or arcuate region 250 remains insulated, and the lateral surface of exposed wire region 302 is positioned beyond (in this case proximally beyond) the boundary of tab or arcuate region 250. The spaced apart electrodes of the embodiments described herein preferably lie along a common radial or circumferential plane.

[0061] Although the tab or arcuate region (second electrode) 250A is shown positioned substantially midway along the length of the longitudinal side L1 of the cutout C1A, the tab or arcuate region 250A may be positioned more proximally or more distally. This changes the longitudinal position of the spaced apart electrodes 250A, 302, as well as the longitudinal position of the defined spark gap between the spaced apart electrodes 250A, 302, and effectively shifts the longitudinal position and focus of the resulting pressure waves, allowing for more effective coverage and / or interaction between adjacent generated pressure waves.

[0062] FIG. 11 shows a cutaway view of the area shown in FIG.

[0063] With continued reference to Figures 4-5 and 6-11, we now turn to Figures 12A-12D, which illustrate features of one embodiment of an exemplary IVL system. Figures 12A-12D sequentially move distally along the exemplary system.

[0064] Beginning with FIG. 12A, immediately distal to the hub 118 as in FIG. 4, a hypotube 402 is provided, which serves as a conduit for fluid infusion and removal and is in fluid communication with the fluid reservoir and pump 114 and the interior of the inflatable portion 210 of the balloon 200. The hypotube 402 may be made of metal, and may be stainless steel. As shown in the structural combination shown in FIG. 12B, distal to the structure of FIG. 12A, an exemplary length of the hypotube 402 may be slightly longer than 1055 mm, although other lengths are within the scope of this disclosure. While FIG. 12B shows a length of 1055 mm, the hypotube 402 extends distally a short distance longer, along which it is overmolded with 72D Pebax® material to form a bond section 403 for, among other things, added bond strength. The hypotube 402 is generally uncoated on its outer and inner surfaces, but includes a polymer, such as Pebax®, near the distal end to aid in joining or bonding, and an adhesive in the proximal end region, also to aid in joining or bonding.

[0065] The hypotube 402 is shown in Figure 12B as terminating at 404 distally. In some embodiments, the hypotube 402 may extend distally from the hub for a distance of approximately 1080 mm. Figure 12B shows a strain relief polyimide conduit PC that extends a distance (e.g., but not limited to, approximately 280 mm) distally from the joining section 403 and has an outer surface coated with 72D Pebax®, also comprising the joining section 403.

[0066] FIG. 12C shows a section comprising an RX port 406, which provides access for a guidewire or other interventional device. The RX port 406 leads to a guidewire conduit 408, which may be comprised of 63D Pebax® tubing comprising a high density polyethylene (HDPE), such as Rezilok, and has an inner surface that may be lined with 63D Pebax®. The guidewire conduit 408 extends distally through the polyimide conduit P and elongate member 230, exiting the system at the distal end of the distal tip 218. The RX port 406 is further described in FIGS. 13A and 13B.

[0067] The proximal end of the outer member 230, made of HDPE, e.g., 63D Pebax® lined with Rezilok, is located just distal to the RX port 406, as shown in FIG. 12C. The outer member 230 continues distally for a length or distance, terminating at a distal end located within the inflatable section 216 of the balloon, as shown and described above, and as shown in FIG. 12D. The elongate member 220 has a proximal end 220P that connects to the polyimide conduit PC described above, and this proximal end 220P has a bonded, e.g., laser reflowed, section 409 to aid in bonding. The elongate member 220 extends through the interior of the outer member 230 and balloon 200 to a point just proximal to the distal tip 218.

[0068] 13A and 13B, the RX port 406 is shown. As shown, a hypotube 410 is provided along the length of the polyimide tube proximal to the RX port 406 for support, and the hypotube may be comprised of a polymer. With additional reference to FIGS. 14A and 14B described below, known devices typically use support wires in place of the hypotube 410, but the inventors have discovered that a polyimide tube with an outer polymer coating that makes up the elongate member 220, which transitions into the solution of the hypotube 410, provides the necessary increased stiffness and support in this critical area.

[0069] FIG. 14A shows a cross-sectional view of the elongate member 220 having the tapered outer member 230, the balloon 200, and the first and second electrode support members ES, ES′. The electrode support members are in operative electrical communication with the voltage pulse generator 110, as described above. A bridge wire WT is provided for operative electrical connection between ES and ES′. The bridge wire is preferably made of tantalum, as opposed to known IVL devices that use copper wire throughout. Tantalum offers significantly increased durability compared to copper. During testing, the copper wire used as the “bridge wire” slowly deteriorated or corroded as the test voltage pulse and the resulting electrical arcs and current flow progressed. Eventually, the copper bridge wire was prone to displacement, disrupting the series connection between the electrode support members ES and ES′. Thus, the tantalum bridge wire was found to provide key durability characteristics, which was one of the features of the present disclosure that allowed for a significantly greater number of electrical arcs (up to 500 and more) to be generated compared to known devices.

[0070] Figure 14B is an enlarged cross-section of the electrode support member of Figure 14A. The elongate member 220 may comprise three layers: a polyimide core, which helps resist heat generated by the electrode during operation, an outer layer of Pebax, and an inner layer of PTFE. Other polymers or blends of polymers may be used in the construction of the elongate member 220.

[0071] In some embodiments, an air or fluid gap 270 is provided between the electrode support member, e.g., ES and / or ES′, and the outer surface of the elongate member 220 to which the electrode support member ES and / or ES′ is joined or operatively connected and at least partially surrounds. The air or fluid gap 270 serves to help dissipate heat generated by electrical arcs occurring across the spark gap between the two spaced apart electrodes 250, 302 described above, allowing fluid within the inflated balloon 200 to flow through the air or fluid gap 270 and around and under portions of the electrode support member ES and / or ES′ to remove heat from the structure. This is another key durability factor of the present disclosure, contributing to the higher frequency and significantly greater number of electrical arcs generated in embodiments of the present disclosure compared to known devices.

[0072] Furthermore, the electrode support members, e.g., ES, ES', are coated with insulating material except for the exposed metal electrode elements, e.g., tabs or arcuate regions 250, and the wire conductors defining the exposed wire electrode elements are also otherwise coated with insulating material. As a result, the surface area of ​​the spaced electrodes in each case is controlled to be relatively small. This contrasts with known IVL systems, which provide concentric metal electrodes with much more exposed metal surface area than is actually needed, resulting in much greater generation of undesirable gases as a by-product of generating an electric arc. This is another key feature of the present disclosure that contributes to durability and improved variability compared to known IVL systems.

[0073] The operative connection or adhesion of electrode support members ES and / or ES' to elongate member 220 in this embodiment is unique in that, as explained above, electrode support members ES and / or ES' are coated or covered with insulating material I. Insulating material I flows down a portion of electrode support members ES and / or ES' to form a connection or attachment between a portion of the underside of electrode support members ES and / or ES' and the outer surface of elongate member 220, while maintaining the required air or fluid gap 270.

[0074] 15A-15E, one embodiment of an electrode support member ES including two electrodes is shown. The electrode support member ES may be used in the IVL system embodiments described above. The electrode support member ES includes a body B, which may be cylindrical and configured to at least partially surround the elongate member 220 as described above. In some embodiments, the electrode support members described herein may not extend entirely circumferentially, as described further below. The embodiment of FIGS. 15A-D includes two radially spaced cutouts: a first cutout C1A and a second cutout C2B. Each cutout C1A, C2B includes opposing longitudinal sides L1, L2, and a proximal end PE and a distal end DE. The body B also includes a longitudinally disposed groove or channel 260 extending along the entire body and configured to receive a portion of an insulated wire conductor. The first cutout C1A includes a longitudinally extending groove or channel 262 extending proximally away from the proximal end PE of the first cutout C1A. The second cutout C2B includes a longitudinally extending groove or channel 264 extending distally away from the distal end DE of the second cutout C2B.

[0075] The electrode support member ES comprises a body formed of conductive material covered with insulating material I as described above. A region along one of the opposing longitudinal sides comprises exposed conductive material with the insulating material covering removed. In the illustrated embodiment of ES, exposed conductive material, e.g., metal, is provided at 250A and 250B along longitudinal side L2 for each of the first and second cutouts C1A and C2B. The embodiment of FIGS. 15A-15E provides the exposed conductive material portions as individual arcuate regions 250A and 250B that extend radially into each cutout C1A and C1B, respectively. Each of the exemplary arcuate regions 250A and 250B defines one electrode of a spaced-apart electrode pair.

[0076] As best seen in Figure 15C, a longitudinal groove or channel 260 is provided that extends the entire length of the electrode support member body B and is configured to receive an insulated portion of one or more wire conductors. Figure 15E shows a cross-sectional view through body B, illustrating that the longitudinal groove or channel 262 may include angled sides, with a small opening at the outermost portion of the groove or channel 262. This angled retention structure may be used to maintain the wires within grooves 260, 262 and / or 264.

[0077] The grooves or channels 260, 262, 264 are provided to maintain the crossing profile of the electrode support member, which is up to the outer diameter of the electrode support member body, and also serve to maintain the wire conductors and associated electrode areas in the proper position within the subject electrode support member.

[0078] FIG. 15D provides a “flattened” view of an exemplary electrode support member body B. The electrode-defining arcuate regions 250A, 250B of exposed conductive material may be substantially centered along the longitudinal side L1 or L2 defining the arcuate regions 250A, 250B. Alternatively, as shown by the dashed lines, one or both of the arcuate regions 250A, 250B of exposed conductive material may be offset from the center of the longitudinal side. Thus, the arcuate regions 250A, 250B may be centered and / or offset from the center along the longitudinal side of interest. In one embodiment, one of the arcuate regions, e.g., 250A, may be longitudinally offset from the position of the other arcuate region, e.g., 250B. This allows the positions of the arcuate regions 250A and 250B (and the resulting positions of the spaced apart electrodes and defined spark gaps) defined by a single electrode support member body B to be adjusted and, in some embodiments, offset from one another both radially and longitudinally. This in turn allows a single electrode support body B having two radially spaced apart electrode pairs to generate pressure waves that generate mechanical forces that are not only radially offset from one another, but also longitudinally offset from one another.

[0079] The formation of spaced electrode pairs and defined spark gaps using the ES of the exemplary embodiments is generally described above and further described below.

[0080] 15A-15E may comprise a proximal electrode support member, such as that shown in FIG. 6, coupled with a more distally spaced electrode support member ES′, described below in FIG. 16A-16D. Additionally, where two or more of the electrode support members ES may be electrically and operatively connected to each other and to the more distally spaced electrode support assembly, one of the electrode support members ES may constitute the most proximal electrode support member, and the remaining electrode support members ES may constitute intermediate electrode support members located between the proximal and distal electrode support members.

[0081] An embodiment of a distal electrode support member ES' is shown in FIGS. 16A-16D. This embodiment, when operatively combined with at least one more proximally spaced electrode support member, such as ES described above, may comprise the exemplary more distally located electrode support member ES' shown in FIG. 6. More fundamentally, and alternatively, this embodiment may be used alone, thereby providing a single electrode support member ES' having two radially spaced electrode pairs when fully assembled. In an alternative embodiment, the single electrode support member ES' may comprise a single pair of spaced electrodes, the spaced electrodes being in operative electrical communication with a first wire conductor in operative electrical communication with a first electrode of the electrode pair and a positive or high terminal of the voltage pulse generator. A second wire conductor may be in operative electrical communication with a second electrode of the electrode pair and a ground or low terminal of the voltage pulse generator.

[0082] The embodiment of Figures 16A-16D also includes two radially spaced cutouts, a first cutout C1C and a second cutout C2D. Each cutout C1C and C2D defines two opposing longitudinal sides L1, L2 and a proximal end PE and a distal end DE, as well as grooves or channels 266, 268 extending proximally from the proximal end PE of each of the first and second cutouts C1C and C2D. Similar to the embodiment of Figures 15A-15E, exemplary arcuate regions 250C and 250D of exposed conductive material are defined along one of the longitudinal sides of the cutouts C1C and C2D, respectively. As best seen in Figure 16D, regions 250C and 250D of exposed conductive material, e.g., metal, are each defined along the longitudinal side L2 of the respective cutouts C1C and C2D. Each arcuate region 250C and 250D forms and defines one electrode of a pair of spaced apart electrodes. As with the embodiment of Figures 15A-15E, the location of one or both of arcuate regions 250C and 250D (and the location of the spark gap defined, if a wire conductor is added, and the resulting pressure wave generated by the spaced apart electrodes) may be longitudinally offset from the center of the defining longitudinal side, as shown by the dashed lines in Figure 16D. This embodiment may not include the longitudinal groove 260 running the entire length of the embodiment of Figures 15A-15E.

[0083] An exemplary spaced-apart electrode pair is shown in FIGS. 17A-17D. An exemplary electrode support member is provided, which may be any of the embodiments described above in FIGS. 15A-16D. The illustrated embodiment is described as electrode support member ES, as described above in connection with FIGS. 14A-14D. A first cutout C1A is shown with a portion of insulated wire conductor 300A positioned or received in a groove or channel 262 extending proximally away from first cutout C1A. A distal-most region 302A of wire conductor 300A has insulation removed, leaving exposed distal-most region 302A of exposed conductive wire. The lateral surfaces, but not the distal end face or surface, of exposed distal-most region 302a of wire conductor 300A, together with the exposed metal of arcuate region 250A, form the spaced-apart electrode pair, defining a spark gap therebetween.

[0084] The location of the exposed conductive wire region 302A is preferably positioned beyond the arcuate region as shown, with the distal end of the exposed wire region located midway between the arcuate region and the distal end of cutout C1A. This preferred dimensioning is indicated by x and y, where x=y in FIG. 17A. Alternatively, the exposed wire region 302A at the distal end of the wire conductor may be positioned generally above the arcuate region to form an alternative embodiment of a spaced-apart electrode pair.

[0085] 17B and 17C illustrate exemplary starting and ending locations of the electrode comprising exposed wire region 302A relative to the spaced-apart electrode comprising exemplary arcuate region 250A. Figures 17B and 17C also illustrate the general manner in which current flow and electrical arcing occurs across a spark gap defined by a spaced-apart electrode pair, with distance A representing the starting spark gap length between the lateral surface of the exposed wire conductor (exemplary first electrode) and the exposed conductive material of the arcuate region (exemplary second electrode), and distance B representing the ending spark gap length. The current flow and resulting electrical arc will translate axially with the translating exposed wire region 302A.

[0086] As the electrical arc initiates and progresses between the spaced apart electrodes 302A and 250A, the electrode consisting of exposed wire region 302A begins to erode and translate, moving effectively axially (proximally in the exemplary embodiment) along arcuate region 250A in the course of the electrical arc, successively engaging different (more proximal) regions of arcuate region 250A. The insulation initially covering wire conductor 300A burns off, exposing successively more of the wire conductor, resulting in a spark gap at distance B at the exemplary end position, as shown in FIG. 17C. As can be seen, the spark gap changes relative position, in this case moving proximally along the longitudinal axis of wire conductor 300A. As the position of the spark gap changes, so does the effective direction of current flow and the resulting electrical arc.

[0087] 17D shows a cross-sectional view through the exemplary electrode support member ES described in connection with FIGS. 15A-15E, illustrating the relative positions and locations of the exemplary first electrode comprised of exposed wire region 302A and the exemplary second electrode comprised of arcuate region 250A, which define a first spaced-apart electrode pair. In addition, relative positions and locations are shown for a second spaced-apart electrode pair that is circumferentially or radially spaced from the first spaced-apart electrode pair. The second spaced-apart electrode pair includes the exemplary second electrode comprised of exposed wire region 302B and the exemplary second electrode comprised of arcuate region 250B. In all embodiments described herein, the electrodes formed by the lateral surfaces of the exemplary exposed conductive wires 302A, 302B and the respective exemplary exposed metal regions, illustrated as arcuate regions 250A, B, are preferably located in substantially the same position relative to the outer surface of the elongate member 220. In other words, the spaced apart electrodes formed by electrodes 302A, 250A and electrodes 302B, 250B may each be located a distance from the outer surface of elongate member 220, with the distance from electrodes 302A, 302B to the outer surface of elongate member 220 being substantially equal to the distance from electrodes 250A, 250B to the outer surface of elongate member 220. This arrangement results in air or fluid gap 270, as further described above. Furthermore, with reference to FIGS. 15A-15E , at least a portion of the lateral surface of the exposed wire section of the first wire conductor may be located between and aligned with first and second longitudinal sides L1, L2 of the cutout, such that the lateral surface of the exposed wire section is spaced apart from and aligned with the exposed metal region. Alternatively, the spaced apart electrodes formed by electrodes 302A and 250A may each be located along the outer surface of elongate member 220.

[0088] In all embodiments, the spaced apart electrodes of the present disclosure are positioned at substantially equal distances from a longitudinal axis through the shaft of the IVL device.

[0089] In some embodiments, the spark gaps, represented by distances A and B, may be of comparable lengths. This is important because it allows for the use of predictable, predetermined voltage magnitudes, which in turn produces a much more controlled pressure output from the generated pressure waves. Ultimately, the pressure output generated with a controlled, known spark gap length contains more consistent, less variable forces than known IVL devices. This is understood to be important in generating less strain on the balloon, which in turn allows for a greater number of maximum voltage pulses, electrical arcs, and generated pressure waves than currently possible with a single catheter or system. For example, known IVL coronary devices have a maximum of 120 voltage pulses. Disclosed embodiments have been demonstrated to effectively generate 300 voltage pulses per catheter in some embodiments, and up to 500 pulses per catheter in some embodiments, with the associated generated pressure waves all within a very narrow distribution and without a significant decrease in generated pressure output over the 300 voltage pulses. In some embodiments, the spark gap may be controlled to be within a predetermined range of lengths, with an exemplary minimum spark gap being 0.004 inches.

[0090] 18A and 18B are similar to the embodiment of FIGS. 17A and 17B, except that the arcuate area electrode is replaced with a cutout C1A' consisting of a raised flat area of ​​exposed metal that functions as an electrode. This arrangement further ensures that the spark gap distance remains substantially the same throughout the series of voltage pulses and arcs executed, as the lateral surfaces of the exposed wire area 302A participate in the electric arc along with the raised flat area. Thus, distances A and B are substantially equal, and each spark gap therebetween is also substantially the same length as distances A and B.

[0091] 19A and 19B show an alternative embodiment similar in function to FIGS. 18A-18B, except that the raised flat region of the electrode replaces the inner surface of cutout C1A″ in electrode support member body B, which has a length or distance of insulation removed, with the area of ​​exposed conductive material functioning as the electrode. This arrangement further ensures that the spark gap distance remains substantially the same throughout a series of voltage pulses and electric arcs executed, as the lateral surfaces of exposed wire region 302 participate in the electric arc with the electrode made of exposed conductive material. Thus, distances A and B are substantially equal, and each spark gap therebetween is also substantially the same length as distances A and B.

[0092] In some embodiments, the shape of the spark gap and associated distance associated with the erosion of the exposed lateral wire surface of the wire conductor may be adjusted to the magnitude of the voltage pulses generated by the voltage pulse generator. In such embodiments, an initial series of voltage pulses at a predetermined magnitude is adjusted to generate an electric arc between spaced apart electrodes separated by a known spark gap distance. In some embodiments, the spark gap distance may change at a known rate during one or more of multiple series of voltage pulses and associated arcs as the electric arc discharge process is performed. Thus, as the erosion process progresses, the exposed lateral wire surface of the wire conductor becomes involved in the arc discharge, and the exposed wire region, e.g., 302A, begins to translate and traverse the electrode (exposed metal) surface of the electrode support member. During this shortening traverse, the spark gap distance may remain substantially the same over the duration of the pulse / arc and / or may vary over the duration of the pulse / arc. The varying spark gap distance can be correlated to a known spark gap distance related to the relative positions of the lateral surfaces of the exposed wire of the wire conductor and the range of positions of engagement of the occurring electric arc along the exposed conductive material area of ​​the electrode support member that constitutes the electrode.

[0093] Thus, the controller may correlate the magnitude of the voltage pulses needed or required for the initial series of voltage pulses and associated electric arcs with a known spark gap distance or distance range, and further through the maximum allowable number of voltage pulses and / or electric arcs for a particular device. The known spark gap distance over time and the resulting arc allows the controller to vary the voltage magnitude as the number of pulses progresses (and the spark gap distance changes) to ensure that (1) an electric arc occurs and / or (2) the pressure output produced by a voltage pulse initiated by the controller at a predetermined magnitude is within a relatively narrow, controlled window. In some embodiments, the controller may determine whether sufficient electrical energy has been released by the energy storage element to generate an electric arc.

[0094] The pairs of spaced apart spark gaps may be arranged and connected in a variety of ways.

[0095] Perhaps the simplest arrangement involves the electrode support member ES' described above in connection with Figures 16A-16D. As shown in Figure 20, the electrode support member ES' includes a first cutout C1C with a first wire conductor 300A received in a groove or channel 266, and a first exposed wire 302A having a lateral surface that serves as a first electrode and positioned in a spaced apart location relative to an exemplary exposed metal arcuate region 250C that serves as a second electrode of a first spaced apart electrode pair.

[0096] As noted in connection with FIG. 17D , the spaced electrodes in all embodiments described herein are preferably located at substantially the same position relative to the outer surface of the elongate member 220. In other words, each spaced electrode may be located a distance from the outer surface of the elongate member 220, with the distance from a first spaced electrode of an electrode pair to the outer surface of the elongate member 220 being substantially equal to the distance from a second spaced electrode of the electrode pair to the outer surface of the elongate member 220. Furthermore, at least a portion of the lateral surface of the exposed wire section of the first wire conductor may be located between the first and second longitudinal sides of the cutout and aligned with the lateral surfaces and exposed metal regions of the first and second longitudinal sides of the cutout. Alternatively, each of the two spaced electrodes of an electrode pair may be located along the outer surface of the elongate member 220.

[0097] The second cutout C2D also includes an exposed metal arcuate region 250D that serves as a third electrode. The second cutout C2D also receives a second wire conductor 300B within a groove or channel 268, the distal end of which includes an exposed wire region 302B whose lateral surface serves as a fourth electrode.

[0098] In operation, when the voltage generator initiates a voltage pulse of sufficient magnitude, current flows through the first wire conductor 300A to the first electrode 302A, across the first spark gap, and to the second electrode 250C in the first cutout C1C, creating an electric arc and a resulting pressure wave. The current continues to flow through the conductive body B of the electrode support member ES' until it reaches the third electrode in the exemplary arcuate region 250D of the second cutout C2D. The current flows from the third electrode across the second spark gap to the fourth electrode, consisting of the second wire conductor 300B and the distal region of the exposed wire 302B, and then along the second wire conductor 300B and back to the negative terminal of the voltage pulse generator. As current flows from arcuate region 250D across the second spark gap to the distal region of exposed wire 302B in second cutout C2D, an electrical arc is generated, resulting in a pressure wave. The second wire conductor is in operative electrical communication with the negative or ground terminal of the voltage generator, and the first wire conductor is in operative electrical communication with the positive or high terminal of the voltage generator.

[0099] FIG. 21 illustrates two electrode support members connected in a series connection. With continued reference to FIGS. 15A-15E , a first, more proximally disposed electrode support member may comprise electrode support member ES, which includes two radially spaced cutouts C1A, C1B, as described, each defining a pair of spaced electrodes with a spark gap therebetween, as described herein. A second (more distal) electrode support member may comprise electrode support member ES′, as described above, which includes two radially spaced cutouts C2C, C2D, similar to ES, each defining a pair of spaced electrodes with a spark gap therebetween.

[0100] 15A-16D, the current flow in FIG. 21 begins when the voltage generator generates a voltage pulse of sufficient magnitude. The resulting current flows distally along the first wire conductor 300A to the first electrode, which is the distal region of the first wire conductor of the exposed wire 302A. The lateral surface of the exposed wire region 302A is in spaced relationship with the arcuate region 250A of the first cutout C1A, which serves as the second electrode of the spaced-apart electrode pair, as described above. As described above in connection with FIG. 17D, the spaced-apart electrodes in all embodiments described herein are preferably located in substantially the same position relative to the outer surface of the elongate member 220. In other words, each of the spaced apart electrodes may be located a distance from the outer surface of the elongate member 220, with the distance from a first spaced apart electrode of the electrode pair to the outer surface of the elongate member 220 being substantially equal to the distance from a second spaced apart electrode of the electrode pair to the outer surface of the elongate member 220. Furthermore, at least a portion of the lateral surface of the exposed wire section of the first wire conductor may be located between the first and second longitudinal sides of the cutout and aligned with the exposed metal region. Alternatively, each of the two spaced apart electrodes of the electrode pair may be located along the outer surface of the elongate member 220.

[0101] Current flowing across this first spark gap creates an electric arc and associated pressure waves.

[0102] Continuing with reference to Figures 15A-16D and 21, current continues to flow through the conductive material of the more proximal body B of the electrical support member ES until it reaches a third electrode comprising a second arcuate region 250B located within a second cutout C2B radially spaced from the first cutout C2A. A second wire conductor 300B or bridgewire comprised of tantalum provides proximal and distal end regions, both of which comprise exposed tantalum wire, with the remainder of the tantalum wire covered by insulation. The proximal end of the exposed tantalum wire comprising the lateral surface of 302B functions as a fourth electrode in this system and is preferably in spaced relationship to the third electrode defined by the second arcuate region 250B.

[0103] As current flows from the third electrode to the fourth electrode in the second cutout C2B, a second electric arc forms across the spark gap, creating a pressure wave.

[0104] The current then flows along the second wire conductor 300B, which is made of tantalum bridgewire, to the more distally spaced electrode support member ES'. The distal exposed wire 302C of the tantalum bridgewire serves as the fifth electrode in this system and has a lateral surface that is located within the first cutout C1C of the electrode support member ES'. The lateral surface of the fifth electrode is spaced apart from the sixth electrode, which is made of the arcuate region 250C of exposed metal in the first cutout C1C of the electrode support member ES'. As the current flows from the fifth electrode across the defined spark gap to the sixth electrode, an electric arc is generated, generating a pressure wave.

[0105] Current continues to flow from the sixth electrode through the conductive body B of the electrode support member ES′ until it reaches a seventh electrode, consisting of an arcuate region of exposed metal 250D in the second cutout C2D of the electrode support member ES′. An eighth electrode, consisting of a third wire conductor 300C with a distal end region of an exposed wire 302D, is formed by the lateral surface of the exposed wire region 302D. The proximal end of the third wire conductor 300C is in operative electrical connection with the ground, low, or negative terminal of a voltage generator. As current flows from the seventh electrode to the eighth electrode in the second cutout C2D of the electrode support member ES′, an electric arc is generated across the spark gap, generating a pressure wave. A portion of the third wire conductor 300C may be received within the groove or channel 260 of the ES, and the proximal end of the third wire conductor 300C is in operative electrical connection with the voltage generator as described above.

[0106] Similar configurations may be made using three or more electrode support members connected in series. For example, a proximal electrode support member ES may be connected in series to a second, more distal electrode support member ES via a tantalum bridgewire, which may then be connected to a distal-most electrode support member ES' via a second tantalum bridgewire. Current flows through the first proximal electrode support member ES as described above, then through the second, more distal electrode support member ES in the same manner, and then through the distal electrode support member ES' as described above.

[0107] It is also possible to combine two (or more) pairs of electrode support members connected in series, with each pair of electrode support members functioning as described above, through the use of a controller and / or multiplexer that selectively applies a voltage to one pair of electrode support members and then selectively applies a voltage to a second pair of electrode support members.

[0108] Additionally, in each of the wiring configurations corresponding to the electrode support member embodiments described above, current flow may be reversed within a given circuit by changing polarity over a series of voltage pulses. In other embodiments, the polarity may be reversed with each voltage pulse. The result of such a polarity change is to change which side of a spaced electrode pair functions as the anode and which side functions as the cathode. Functionally, this may be advantageous in that it increases the number of resulting electric arcs that can be generated between two spaced electrodes, particularly if one of the spaced electrodes wears or corrodes more quickly than the other electrode of the spaced electrode pair.

[0109] FIG. 22 shows a handle, which may be in operative communication with and connected to a console, which may include a processor and operatively connected memory as described in connection with FIG. 1 for executing instructions, and the voltage pulse generator 110 described above. In this embodiment, the handle includes or is in communication with an EPROM (erasable read-only program memory), which may be in operative communication with the processor and / or memory. The EPROM may provide treatment parameters, which may be specific to a particular model of IVL device, e.g., a balloon of a specified length and / or a balloon with a specified number of electrode support members and / or spark gaps. Additionally, the processor and / or memory may store treatment parameters for comparing ongoing treatment monitored by the processor with stored treatment parameters. The processor may also generate a connection log, monitor the number of pulses (and the maximum number allowed), and generate a connection log. FIG. 23 provides a schematic flow of data involving the EPROM in the IVL system of the present disclosure.

[0110] Having described certain key features of the exemplary IVL systems herein, we now turn to the functional results of those exemplary systems. Comparative pressure output tests were performed on known IVL systems operated according to their own instructions for use, and on a test system according to the present disclosure.

[0111] The test methods and materials included a comparison of the test device with a known IVL device. Each device included a catheter, a balloon, two radially spaced electrode pairs within the balloon, and a voltage pulse generator connected to the electrode pairs. Test balloon sizes included 2.5 x 12 mm and 4.0 x 20 mm. Known balloon sizes included 2.5 x 12 mm, 4.0 x 20 mm, 2.5 x 40 mm, and 4.0 x 40 mm. Each tested IVL system had substantially the same spacing between adjacent longitudinally spaced electrode pairs. The test device included an unamplified ONDA HNR-0500 (Serial Numbers 2149 (calculated May 3, 2023) and 2160 (calculated May 5, 2023)) needle hydrophone. The hydrophone had an effective diameter of 2.5 mm. The hydrophone was calibrated and is owned by Onda Corporation. The frequency response is flat from 0.5 MHz to 10 MHz within + / - 6 dB, with a measurement uncertainty of 1.5 dB from 0.5 to 1 MHz and 1 dB from 1 to 10 MHz. The test device and the known device were immersed in a water bath. Using the test methods and materials described above, a total of 1,440 voltage pulses were performed with the known system and the resulting pressure output was measured, and a total of 13,320 voltage pulses were performed with the test system and the resulting pressure output was measured.

[0112] The pressure output test method consisted of the following steps for each device tested:

[0113] 1. Place the subject's IVL device balloon into the water bath.

[0114] 2. Place the hydrophone approximately 2.89 mm distal to the spark gap of interest, providing an approximately 5 mm offset between the hydrophone and the longitudinal axis of the catheter.

[0115] 3. Generate a voltage pulse with a predetermined magnitude.

[0116] 4. Move the catheter so that the hydrophone is positioned approximately 0.9375 mm proximal to the spark gap of the electrode pair of interest.

[0117] 5. Repeat steps 1-4 until the hydrophone is positioned at least 2.89 mm proximal to the target spark gap.

[0118] 6. Rotate the catheter axially by 45 degrees, 90 degrees, 135 degrees, and 180 degrees and repeat steps 1-5.

[0119] Comparative testing and feature selection

[0120] Pressure Output Variability

[0121] 24 provides a data plot of pressure output (initial peak pressure) for a known IVL system and a test IVL system according to the present disclosure. As is immediately apparent visually, the pressure output of the known system fluctuates widely. In contrast, the pressure output data for the test system is relatively tightly controlled and exhibits relatively low variability compared to the variability of the known system. A summary of the data is provided in Table 1.

[0122] [Table 1]

[0123] Thus, the coefficient of variation ("CV"), a measure of variability within a data set, was 39.3% for the pressure output data of the known system and 23.8% for the pressure output data of the test system. Therefore, it can be reasonably concluded that the pressure output data of the test system was more controlled and substantially less variable than the pressure output data of the known system. Therefore, key features of the IVL system can be used to enable a CV of less than 35% within a series of pressure output data. More preferably, the CV within a series of pressure output data is less than 30%, and even more preferably, the CV within a series of pressure output data is less than 25%. As noted above, the IVL system described herein is more durable (many more pulses / electrical arcs / pressure waves per catheter), more efficient (higher frequency of pulses / electrical arcs / pressure waves), and allows for a much more controlled pressure output from the generated pressure waves than known IVL systems.

[0124] Force required to pass through the vascular system

[0125] The test system and a known system (Shockwave Medical C2 IVL catheter) were subjected to standard force tracking tests using an ASTM F2394 tracking device, as shown in Figure 25. Each tested system contained two emitters, each consisting of spaced electrodes. Each tested system was translated through the standard device shown, while the force required to move the tested catheter from the beginning to the end of the device was tracked. Both the test system and the known system were two-emitter designs (two spaced electrode pairs, spaced longitudinally from each other), and the balloon size was 3.0 mm x 20 mm for both the test system and the known system. The ASTM F2394 tracking device was filled with water and lubricated. The test catheter and the known catheter were tracked through the wires through the model until the distal tip reached the end of the model. The peak force was recorded and observed on the plot shown in Figure 25. This comparative test measures the relative resistance through a tortuous vasculature.

[0126] As shown, the average peak force for the test system was 368.425 grams, while for the known system, the average peak force was 408.233 grams. This represents a 9.75% reduction in the force required for the test system compared to the known system. The % difference between the two average peak force values ​​is 10.8%.

[0127] Thus, the average peak force for the embodiment of the test system through the ASTM F2394 tracking instrument is approximately 9.75% less than the average peak force of the known system.

[0128] Certain embodiments of the test system may provide an average peak force through an ASTM F2394 tracking device that is at least 9.5% less than the average peak force of known systems.

[0129] Certain embodiments of the test system may provide an average peak force through an ASTM F2394 tracking device that is at least 9% less than the average peak force of known systems.

[0130] Certain embodiments of the test system may provide an average peak force through an ASTM F2394 tracking device that is at least 8% less than the average peak force of known systems.

[0131] Certain embodiments of the test system may provide an average peak force through an ASTM F2394 tracking device that is at least 6% less than the average peak force of known systems.

[0132] Certain embodiments of the test system may provide an average peak force through an ASTM F2394 tracking device that is at least 5% less than the average peak force of known systems.

[0133] Therefore, the test system passed through the test fixture with a peak force of less than 405 grams from start to finish.

[0134] Additionally, the test system passed through the test fixture with a peak force of less than 400 grams from start to finish.

[0135] The test system also passed through the test fixture with a peak force of less than 375 grams from start to finish.

[0136] The test system also passed through the test fixture with a peak force of less than 370 grams from start to finish. As a result, the peak forward force of the test system can be in the range of about 400 grams to about 405 grams. The peak forward force of the test system can also be in the range of about 375 grams to about 405 grams. The measured peak forward force of the test system may also be in the range of about 370 grams to about 405 grams.

[0137] Additionally, Table 2 below provides a partial summary of the functional improvements and enhancements provided by embodiments of the present disclosure over known systems, listing some of the disclosed features that lead to those improvements and enhancements.

[0138] [Table 2-1]

[0139] [Table 2-2]

[0140] [Table 2-3]

[0141] The description of the invention and its applications set forth herein is for illustrative purposes only and is not intended to limit the scope of the invention. Features of various embodiments may be combined with other embodiments within the contemplation of the invention. Variations and modifications of the embodiments disclosed herein are possible, and upon review of this patent document, those skilled in the art will recognize practical substitutes and equivalents for the various elements of the embodiments. These and other variations and modifications of the embodiments disclosed herein can be made without departing from the scope and spirit of the invention. [Explanation of symbols]

[0142] 12 IVL System 15 Guidewire 114 Catheter Assembly 16 components, balloons 17 Gap 18 electrodes 20 Electrical Pulse Generating System 22 IVL Control System 24 processors 26 memory 28 circuits 100 IVL System 110 Voltage Pulse Generator 112 Controller 114 Fluid reservoir / fluid pump device 120 Connector 118 Hub 116 Catheter and Balloon Elements 200 balloons 202 Proximal Section 203 Unjoined Section 204 Proximal part 206 Distal Section 207 Proximal part 210 Inflatable part 212 Tapered proximal section 214 Tapered Distal Section 216 Substantially cylindrical section, expandable section 218 Distal Tip 220 Long Members 220P proximal end 230 Tapered outer member 232 Distal tapered section 234 Outer surface, cylindrical section 250, 250A, 250B, 250C, 250D Tab or Arcuate Area, Electrode 260, 262, 264, 266, 268 Groove or channel 270 Air or Fluid Gap 300, 300A, 300B Wire Conductor 302 wire distal end region, electrode 302A Distal most region, wire region 402, 410 Hypotube 403 Junction Section 406 RX port 408 Guidewire conduit 409 sections P Fluid transfer pipe O opening BP Marker Band W Wire Conductor C1A, C1B, C2A, C2B, C1C, C2D, C1C, C2C, C2D, C1A', C1A'' cutout PC Polyimide Conduit L1, L2 Longitudinal sides ES, ES' electrode support member B body PE proximal end DE distal end

Claims

1. a pulse generator 110 having positive and negative terminals and an interconnect; a cable having a proximal end, the cable having an interconnection 120 at the proximal end configured to interconnect with the interconnection of the pulse generator 110; an actuation handle located along the cable; an elongate member 220 having an outer surface; a fluid-inflatable balloon (200) located at or near the distal end of the elongate member (220); one or more pairs of spaced apart electrodes are disposed within said fluid-inflatable balloon; a first pair of the one or more pairs of spaced apart electrodes; a first electrode 302A comprising a first wire conductor 300A surrounded by insulation and operatively connected at a proximal end to the positive terminal of the pulse generator 110 and having a distal end, the first wire conductor 300A comprising an exposed wire section 302A extending proximally from the distal end a length defining the first electrode 302A; a second electrode spaced from the first electrode and formed from a first electrode support member ES, the first electrode support member ES having a length of body B attached to and at least partially surrounding an outer surface of the elongate member 220; a groove 260 defined along the length of the body B; the first electrode support member body ES comprises a conductive material covered with an insulating material I, the conductive material defining a first cutout C1A having an arcuate region that defines the second electrode 250A, the arcuate region being located along one longitudinal side of the first cutout and extending toward an opposite longitudinal side of the first cutout; a lateral surface of the arcuate region defining the second electrode (250A) having the insulating material removed; the exposed wire section defining the first electrode (302A) extending from the distal end of the first wire conductor is disposed within the first cutout (C1A), whereby a lateral surface of the exposed wire section defining the first electrode (302A) is located between and aligned with longitudinal sides (L1, L2) of the first cutout (C1A) and is radially spaced from the lateral surface of the arcuate region defining the first electrode (302A) of the first cutout (C1A), thereby defining a spark gap between the lateral surface of the exposed wire defining the first electrode (302A) and the lateral surface of the arcuate region defining the second electrode (250A).

2. 2. The IVL system of claim 1, wherein the first electrode is spaced a distance from the outer surface of the elongate member, the second electrode is spaced a distance from the outer surface of the elongate member, and the distances from the outer surface of the elongate member to each of the first and second electrodes are substantially equal.

3. 3. The IVL system of claim 1, wherein at least a portion of the lateral surface of the exposed wire section of the first wire conductor is located between the first longitudinal side and the second longitudinal side of the cutout and is aligned with the lateral surface of the arcuate region.

4. 4. An IVL system according to claim 1, wherein the first cutout has a first channel at the proximal end thereof extending proximally away from the first cutout, and a portion of the distal end of the insulated portion of the first wire conductor is received within the first channel.

5. 5. An IVL system according to claim 1, wherein the distal end of the first wire conductor is initially positioned at half the distance between the distal side of the arcuate region and the distal end of the first cutout.

6. 6. The IVL system of claim 1, wherein the exposed wire section of the first wire conductor is initially located distal to the arcuate region.

7. 7. The IVL system of claim 1, wherein a portion of the exposed wire section of the first wire conductor initially lies laterally across a portion of the arcuate region.

8. 8. An IVL system according to claim 1, wherein the distal end of the first wire conductor is located at half the distance between the center of the arcuate region and the distal end of the first cutout.

9. 9. The IVL system of claim 1, further comprising a ground wire conductor in operative electrical communication with the second electrode and the negative terminal of the pulse generator.

10. Further comprising a second pair of the one or more pairs of spaced apart electrodes, the second pair comprising: a third electrode defined by a first electrode support including a second cutout circumferentially spaced from the first cutout, the second cutout defining an arcuate region having a lateral surface, the lateral surface being located along one longitudinal side of the second cutout and extending toward an opposite longitudinal side of the second cutout, the third electrode being in operative electrical communication with the first pair of the one or more pairs of spaced apart electrodes; 10. The IVL system of claim 1, further comprising: a fourth electrode spaced from the third electrode and comprising a second wire conductor surrounded by insulation, the second wire conductor comprising an exposed wire section located between and aligned with the longitudinal sides of the second cutout and radially spaced from the lateral surface of the arcuate region of the second cutout to define a spark gap between the lateral surface of the exposed wire section of the second wire conductor and the arcuate region of the second cutout.

11. 11. The IVL system of claim 10, wherein the third electrode is located at a distance from the outer surface of the elongate member, the fourth electrode is located at a distance from the outer surface of the elongate member, and the distances of the third electrode and the fourth electrode from the outer surface of the elongate member are substantially equal.

12. 13. The IVL system of claim 10, wherein the second cutout further comprises a second channel at the proximal end of the second cutout, a portion of the proximal end of the insulated portion of the second wire conductor being received within the second channel, and the second channel extending proximally away from the second cutout.

13. 13. The IVL system of claim 10, wherein the distances of the first, second, third, and fourth electrodes from the outer surface of the elongate member are substantially equal.

14. 14. The IVL system of claim 10, wherein at least a portion of the lateral surface of the exposed wire section of the first wire conductor is located between the first longitudinal side and the second longitudinal side of the cutout and is aligned with the lateral surface of the arcuate region.

15. 15. An IVL system according to one or more of claims 11 to 14, wherein the distal end of the second wire conductor is located at half the distance between the distal side of the arcuate region of the second cutout and the distal end of the second cutout.

16. 16. The IVL system of claim 11, wherein the exposed wire section of the second wire conductor is located distal to the arcuate region of the second cutout.

17. 17. The IVL system of claim 11, wherein a portion of the exposed wire section of the second wire conductor lies across a portion of the arcuate region of the second cutout.

18. 18. An IVL system according to one or more of claims 11 to 17, wherein the proximal end of the first wire conductor is located at half the distance between the center of the arcuate region and the distal end of the second cutout.

19. 19. The IVL system of claim 11, further comprising a proximal end of the second wire conductor configured to be in operative electrical communication with the negative terminal of the pulse generator.

20. 20. The IVL system of claim 11, wherein the first and second electrodes define a first spark gap, the third and fourth electrodes define a second spark gap, and the first spark gap is circumferentially spaced from the second spark gap.

21. 21. The IVL system of claim 11, wherein the first spark gap and the second spark gap are electrically connected in a series configuration when a current is passed across each of the first spark gap and the second spark gap.

22. a pulse generator 110 having positive and negative terminals and an interconnect; a cable having a proximal end, the cable having an interconnection 120 at the proximal end configured to interconnect with the interconnection of the pulse generator 110; an actuation handle located along the cable; an elongate member 220 having an outer surface; a fluid-inflatable balloon (200) located at or near the distal end of the elongate member (220), wherein one or more pairs of spaced apart electrodes are disposed within the fluid-inflatable balloon; a first pair of the one or more pairs of spaced apart electrodes; a first electrode 302A comprising a first wire conductor 300A surrounded by insulation and operatively connected at a proximal end to the positive terminal of the pulse generator 110 and having a distal end, the first wire conductor 300A comprising an exposed wire section extending proximally from the distal end a length that constitutes the first electrode 302A; a second electrode (250A) spaced apart from the first electrode (302A) and comprising a first electrode support member (ES), the first electrode support member (ES) being attached to an outer surface of the elongate member (220) and having a body (B) at least partially surrounding the outer surface; a body (B) of the first electrode support member (ES) having a length, a groove (260) along the length of the first electrode support member body, and conductive material covered with an insulating material (I) defining a first cutout (C1A) having an exposed metal area, the exposed metal area defining a second electrode (250A) located along a first longitudinal side of the first cutout; the lateral surfaces of the exposed metal regions are freed of the insulating material I; the exposed wire section extending from the distal end of the first wire conductor and defining the first electrode (302A) is disposed within the first cutout (C1A), whereby a lateral surface of the exposed wire section defining the first electrode (302A) is located between and aligned with longitudinal sides (L1, L2) of the first cutout (C1A) and is radially spaced from a lateral surface of the exposed metal region of the first cutout (C1A) defining the second electrode (250A), thereby defining a spark gap between the lateral surface of the exposed wire of the first electrode (302A) and the lateral surface of the exposed metal region of the second electrode (250A).

23. 23. The IVL system of claim 22, wherein the exposed metal area comprises a flat surface.

24. 24. The IVL system of claim 23, wherein the flat surface extends away from the first longitudinal side toward a second, opposite longitudinal side of the first cutout.

25. 25. An IVL system according to one or more of claims 22 to 24, wherein the distal end of the first wire conductor is initially located at half the distance between the distal side of the exposed metal area and the distal end of the first cutout.

26. 26. The IVL system of claim 25, wherein the exposed wire section of the first wire conductor is initially located distal to the exposed metal region.

27. 27. The IVL system of claim 26, wherein a portion of the exposed wire section of the first wire conductor initially lies flanking a portion of the exposed metal area.

28. 25. An IVL system according to one or more of claims 22 to 24, wherein the distal end of the first wire conductor is located at half the distance between the center of the arcuate region and the distal end of the first cutout.

29. 29. The IVL system of claim 22, further comprising a ground wire conductor in operative electrical communication with the second electrode and the negative terminal of the pulse generator.

30. Further comprising a second pair of the one or more pairs of spaced apart electrodes, the second pair comprising: a third electrode defined by a first electrode support including a second cutout circumferentially spaced from the first cutout, the second cutout defining an exposed metal region having a side surface, the side surface having the insulating material removed, located along a first longitudinal side of the second cutout and extending toward a second, opposite longitudinal side of the second cutout, the third electrode in operative electrical communication with the first pair of the one or more pairs of spaced apart electrodes; 30. The IVL system of claim 22, further comprising: a fourth electrode spaced from the third electrode and comprising a second wire conductor surrounded by insulation, the second wire conductor comprising an exposed wire section located between and aligned with the longitudinal sides of the second cutout and radially spaced from the lateral surface of the exposed metal region of the second cutout to define a spark gap between the lateral surface of the exposed wire section of the second wire conductor and the exposed metal region of the second cutout.

31. 31. The IVL system of claim 30, wherein the third electrode is located at a distance from the outer surface of the elongate member, the fourth electrode is located at a distance from the outer surface of the elongate member, and the distances of the third electrode and the fourth electrode from the outer surface of the elongate member are substantially equal.

32. 32. The IVL system of claim 31, wherein the second cutout further comprises a second channel at a proximal end of the second cutout, a portion of the proximal end of the insulated portion of the second wire conductor being received in the second channel, and the second channel extending proximally away from the second cutout.

33. 33. The IVL system of any one of claims 30 to 32, wherein the distances of the first, second, third, and fourth electrodes from the outer surface of the elongate member are substantially equal.

34. 34. An IVL system according to one or more of claims 30 to 33, wherein the distal end of the second wire conductor is located at half the distance between the distal side of the exposed metal area of ​​the second cutout and the distal end of the second cutout.

35. 35. The IVL system of claim 30, wherein the exposed wire section of the second wire conductor is located distal to the exposed metal area of ​​the second cutout.

36. 36. An IVL system according to one or more of claims 30 to 35, wherein the proximal end of the first wire conductor is located at half the distance between the center of the arcuate region and the distal end of the second cutout.

37. 37. The IVL system of claim 30, further comprising a proximal end of the second wire conductor configured in operative electrical communication with the negative terminal of the pulse generator.

38. 38. The IVL system of claim 30, wherein the first and second electrodes define a first spark gap, the third and fourth electrodes define a second spark gap, and the first spark gap is circumferentially spaced from the second spark gap.

39. 39. The IVL system of claim 30, wherein the first spark gap and the second spark gap are electrically connected in a series configuration when a current is passed across each of the first spark gap and the second spark gap.

40. 1. An intravascular disruption device comprising at least one pair of spaced apart electrodes in operative electrical communication with a voltage pulse generator, A first electrode 302A, a first wire conductor (300A) having a proximal end and a distal end, the first wire conductor (300A) surrounded by insulation (1) and operatively connected to a positive terminal of the pulse generator (110) at the proximal end of the first wire conductor (300A), the first wire conductor (300A) including an exposed wire section defining a first electrode (302A) having a lateral surface extending a length proximally from the distal end; a first electrode 302A comprising: a second electrode (250C) spaced apart from the first electrode (302A) to form a spark gap therebetween; Electrode support member ES' having body B and a second electrode 250C comprising: the body (B) of the first electrode support member includes a conductive material covered with an insulating material (I), the conductive material defining a first cutout (C1C) having an exposed metal area located along a first longitudinal side (L1) of the first cutout (C1C), the exposed metal area including a lateral surface facing a second, opposite longitudinal side (L2) of the cutout (C1C) and a channel (266) leading proximally away from the first cutout (C1C); a portion of the first wire conductor 300A is received in the channel 262; the exposed wire section of the first electrode 302A is located between and aligned with the longitudinal sides L1, L2 of the first cutout C1C and is radially spaced from the lateral surface of the exposed metal region defining the second electrode 302A to form a spark gap between the lateral surface of the first electrode 302A and the second electrode 250C of the first cutout C1C.

41. 41. The intravascular disruption device of claim 40, wherein at least a portion of the lateral surface of the exposed wire section of the first wire conductor is located between the first longitudinal side and the second longitudinal side of the cutout and aligned with the exposed metal region.

42. 1. An electrode for an intravascular lithotripsy ("IVL") system, comprising: an electrode support member ES comprising a body B formed of a conductive material and covered with an insulating material I, said body B being operatively attached to an elongated member 220 and configured to at least partially surround said elongated member 220; said electrode support member ES comprising: a first cutout C1A defined by the body B, a first exposed metal area defining an electrode 250A located along a first longitudinal side L1 of the first cutout C1A; and a channel 262 leading proximally away from the first cutout C1C. a first cutout portion C1A comprising: a second cutout portion C2B defined by the main body B, the second cutout portion C2B being circumferentially spaced from the first cutout portion C1A, the second cutout portion C2B comprising: a second exposed metal region defining an electrode 250B located along a first longitudinal side L1 of the second cutout C2B; and a channel 264 leading distally away from the second cutout C2B. a second cutout C2B comprising: An electrode comprising:

43. 1. An electrode for an intravascular lithotripsy ("IVL") system, comprising: an electrode support member ES′ comprising a body B formed of a conductive material and covered with an insulating material I, said body B being operatively attached to and configured to at least partially surround the elongated member 220, said electrode support member ES′ comprising: a first cutout C1C defined by the body B, a first exposed metal area defining an electrode 250C located along a first longitudinal side L1 of the first cutout C1C; and a first channel 266 leading proximally away from the first cutout C1C. a first cutout C1C comprising: a second cutout portion (C2D) defined by the main body (B), the second cutout portion (C2D) being circumferentially spaced from the first cutout portion (C1C), the second cutout portion (C2D) comprising: a second exposed metal region defining an electrode 250C located along a first longitudinal side L1 of the second cutout C2D; and a channel 268 leading proximally away from the second cutout C2B. a second cutout C2D comprising: An electrode comprising:

44. 1. An intravascular lithotripsy ("IVL") system with improved variability in pressure output, comprising: An elongated member; a fluid-fillable balloon formed from a material having an outer surface and surrounding a distal region of the elongate member; at least two pairs of spaced apart electrodes located within the fluid-fillable balloon along the elongate member, the at least two pairs of spaced apart electrodes being longitudinally spaced apart from one another along the elongate member, each pair of spaced apart electrodes forming a spark gap; a voltage pulse generator in operative electrical communication with the at least one pair of spaced apart electrodes; a controller configured to control the voltage pulse generator; the IVL system is configured to generate a plurality of electric arcs across the at least two pairs of spaced apart electrodes, each of the plurality of electric arcs being generated in response to a voltage pulse provided by the voltage pulse generator; each of the plurality of electric arcs generated generates a pressure wave that travels through the fluid-fillable balloon and the material forming the fluid-fillable balloon and through a water bath in which the balloon is immersed; An intravascular lithotripsy ("IVL") system, wherein the peak pressures of all of said generated pressure waves, as measured by an ONDA HNR-0500 needle hydrophone positioned at predetermined locations relative to a spark gap and the longitudinal axis of said elongate member, comprise a coefficient of variation ("CV") of less than 35%.

45. 45. The IVL system of claim 44, wherein the CV is less than 30%.

46. 45. The IVL system of claim 44, wherein the CV is less than 25%.

47. An elongated member; a fluid-fillable balloon formed from a material and measuring 3 mm x 20 mm folded around the distal region of the elongate member; two pairs of spaced apart electrodes located within the fluid-fillable balloon along the elongate member, the two pairs of spaced apart electrodes being longitudinally spaced apart from one another along the elongate member; 1. An intravascular rupture ("IVL") system, wherein when a catheter undergoes a standard tracking force test using a water-filled ASTM F2394 tracking device, the measured peak forward force of the catheter from the beginning to the end of the ASTM F2394 tracking device is within the range of about 400 grams to about 405 grams.

48. 48. The IVL system of claim 47, wherein the measured peak propulsive force is in the range of about 375 grams to about 405 grams.

49. 48. The IVL system of claim 47, wherein the measured peak propulsive force is within the range of about 370 grams to about 405 grams.

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